The Astronomical Society of the Toms River Area
ASTRA club message board

It is currently Sun Jan 20, 2019 5:49 am

All times are UTC - 5 hours

Post new topic Reply to topic  [ 3 posts ] 
Author Message
PostPosted: Thu Jun 02, 2016 2:38 pm 
User avatar

Joined: Wed Oct 12, 2011 8:57 pm
Posts: 604
Above-average seeing in Whiting, NJ drew me outside my home last night for a midnight view of Mars. Mars' apparent diameter was 18.6 arc-seconds, virtually unchanged from what it was at its closest approach to Earth, on May 30. The North Polar Cap (NPC) could be seen quite well, especially with a light green #56 filter. The surface of Mare Sirenum (Sea of Sirens) appeared as a dark region. I used a 5.5-inch apochromatic refractor and a Tele Vue 4.7 mm Ethos eyepiece for a magnification of 149X. A black towel over my head provided some relief from street and porch lights.

Mars will remain above 18 arc-seconds in diameter until June 13. On that date it will be highest in the sky at 10:53 pm EDT.

Matthew M.

PostPosted: Sat Jun 04, 2016 7:19 pm 

Joined: Fri Nov 25, 2011 10:49 am
Posts: 220
Good report Matthew. Appears the hemisphere of Mars busy with albedo features is rotating into view.

If the seeing conditions permit try going up to 200x. I have noticed improved detail with increasing magnification. I have not yet tried reducing glare around Mars using a neutral density filter.

Vic Palmieri

PostPosted: Tue Jun 07, 2016 10:34 am 
User avatar

Joined: Thu Oct 13, 2011 12:53 pm
Posts: 268
Location: Maple Shade, NJ
At long last, I've finished my long-winded report...

I too was out for a look at Mars last Wednesday night from about 1:30 to 2:00 am EDT (so it was actually Thursday morning, June 2nd). I was going to load my 80 mm (3.15”) f/6 apo refractor in the car for a morning-twilight run to my site with a super-low eastern horizon, where I intended to look for Mercury before sunrise, but I also hoped to see Uranus' disc and a couple of stellar occultations by the moon. When I stepped out around 1:30 am, I saw ruddy Mars gleaming steadily in a hazy sky, which suggested the possibility of good seeing, so I set up my small scope, which only takes a moment (I leave the quick-release mounting plate attached to it so I can pop it onto a photo tripod with a video head).

Indeed, a look through the scope confirmed the seeing was pretty good, so I quickly ran the magnification up to 160x using my 3 to 6 mm Nagler zoom at 3 mm, my shortest focal length eyepiece, so it’s the maximum magnification I can get without a Barlow (but 160x is already at 50.8x per inch of aperture). Although the edges of the Martian disc were slightly rippling from seeing effects, the disc itself looked steady.

Unfortunately, the “blah” side of Mars was facing earth (the central meridian was about 165° at 1:45 am). The disc had a distinct overall light reddish-brown color with a dark band across the bottom. I was using a diagonal, so north was up with east to the right. Checking various Mars maps, the dark band consisted of Mare Sirenum, the western end of which was beginning to rotate off the disc, and Mare Cimmerium that was beginning its rotation onto the disc from the east. A whitish spot was visible at the upper limb, which was consistent with the North Polar Cap.

I also observed Saturn at 160x. It was a lovely sight with a generally creamy-yellow color. The rings are now tilted about 26°, which is near their maximum, so the separation between the ball and the rings was quite obvious. The Cassini Division was not difficult to see in the anses of the rings, and a vaguely darkened horizontal band (the North Equatorial Belt) was visible on the ball.

At 1:45 am EDT on June 2, Mars was 18.59" x 18.49" diameter (equatorial x polar) while the ball of Saturn was 18.44" x 16.98" diameter, so these two planets were nearly the same apparent size (not counting the rings of Saturn, which were about 43" across). However, Saturn was slightly better positioned at 29° altitude (culmination was at 1:04 am June 2 for my location near 40°N-75°W) compared to Mars at 24° altitude in (culmination was at 11:58 pm on June 1).

I then packed the scope in the car and went back in for a nap. However, when I stepped out again at 4 am, the sky was largely overcast. I decided that since I was up anyway, I’d drive a few miles to my low-horizon spot and see what happens. By time I got there, it was completely overcast, so after a few minutes, I just went back home. I hadn't spotted Mercury yet this elongation, and it would have been the first time since the transit on May 9th (and additionally, the first time since last seeing it as a bright object in the evening sky on April 27th).

The weather finally cooperated and I spotted Mercury on June 6th at 4:44 am EDT with my 16x70 binoculars, so that keeps my sighting streak intact at 35 elongations in a row since January 2011. I also spotted Uranus again with the binoculars, but I didn't take the scope, so I didn't see the disc. Of course, by then the moon was in the evening sky.

Joe Stieber

Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 5 hours

Who is online

Users browsing this forum: No registered users and 1 guest

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: